Survey of termite-inhabited soil and mosquito breeding sites in Lucknow,India for potential mycopathogens of Anopheles stephensi

A mycological survey was carried out on the fruit surface of Indian jujube during its growth period (before harvest). A total of 32 microfungi belonging to 20 genera were isolated by surface washing technique. Artificial inoculations with the isolated myco-propagules were also performed in mature jujube fruits and most of them were able to cause rot of varying severity. However, Monodictys castaneae, Eupenicillium lapidosum, Paecilomyces fumosoroseus, Trichurus spiralis and Acremonium spp., although present on the fruit surface, were not able to cause rot, indicating lack of specific macerating enzymes necessary for postharvest pathogenesis. This revised version was published online in June 2006 with corrections to the Cover Date.     

Assessment of plant secondary metabolites in oil palm seedlings after being treated with calcium,copper ions and salicylic acid

The effect of calcium, copper ions and salicylic acid (SA) amendment on the incidence of basal stem rot and activity of secondary metabolites in oil palm seedlings were investigated in glasshouse study. Disease incidence (DI) in positive control (T8) was 75% at nine months after inoculation (9 MAI). However, weekly pre-immunisation with Ca^2+?+^?Cu^2+?+^?SA prior to inoculation significantly suppressed DI and delayed disease onset as noted in T7. In the present study, the lowest %DI was observed in T7 (15%) followed by T1, T5, T6, T3, T4 and T2. The Ca²⁺, Cu²⁺ and SA amendments were resulted in earlier and higher accumulation of plant secondary metabolites as noted in leaves, stems and root tissues in response to invasion by Ganoderma boninense. High total phenolic content concentration was detected in T7 (leaf: 233.38 ± 0.12 mg/g; stem: 132.78 ± 0.04 mg/g and root: 86.98 ± 0.28 mg/g). Similar trend was obtained in peroxidase activity, total lignin content and hydrogen peroxide scavenging activity. These results suggested that it could be due to the accumulation of phenolics, peroxidase activities, lignin content and hydrogen peroxide scavenging activities in oil palm seedling tissues which might have collectively contributed to induce resistance against G. boninense.     

Population dynamics of Macrophomina phaseolina in relation to disease management: A review

Macrophomina phaseolina (Tassi) Goid. causes seedling blight, charcoal rot, leaf blight, stem and pod rot on over 500 plant species in different parts of the world. The pathogen survives as sclerotia formed in host tissues which are released into the soil as tissue decay. Low soil moisture is considered the more important predisposing factor for M. phaseolina-induced diseases than high temperature. The intensity of the disease on a crop is related to the population of viable sclerotia in the soil and abiotic factors. The influence of various management strategies in reducing the number of viable propagules of the pathogen in the soil has been studied in order to minimize the impact of the disease. Any management approach that reduces inoculum density in the soil may reduce disease incidence on the host. However, to reduce inoculum density, quantitative determination of viable propagules from soil is necessary in order to understand the effect of management strategies on the population dynamics of this pathogen. Considerable work has been done on organic amendments, changing crop sequences with tolerant crops, fumigants, herbicides and tillage in managing M. phaseolina populations in the soil and the resulting disease. Solarization has been used in controlling M. phaseolina in different countries where this pathogen is causing disease on economically valuable crops. However, this method of soil disinfestation was effective in eliminating viable populations at the top soil layer although by combining other approaches its effectiveness was improved at lower soil depth. Use of biological control agents with or without organic amendments or after solarization has emerged to be a practical management approach in the control of M. phaseolina. In this paper, an attempt has been made to review those research findings where the influence of various management approaches on survival of M. phaseolina mainly sclerotia have been investigated.     

Potential of ligninolytic enzymatic complex produced by white‐rot fungi from genus Trametes isolated from Bulgarian forest soil

Because of the crucial role of ligninolytic enzymes in a variety of industrial processes, the demand for a new effective producer has been constantly increasing. Furthermore, information on enzyme synthesis by autochthonous fungal strains is very seldom found. Two fungal strains producing ligninolytic enzymes were isolated from Bulgarian forest soil. They were identified as being Trametes trogii and T. hirsuta. These two strains were assessed for their enzyme activities, laccase (Lac), lignin peroxidase (LiP) and Mn‐dependent peroxidase (MnP) in culture filtrate depending on the temperature and the type of nutrient medium. T. trogii was selected as the better producer of ligninolytic enzymes. The production process was further improved by optimizing a number of parameters such as incubation time, type of cultivation, volume ratio of medium/air, inoculum size and the addition of inducers. The maximum activities of enzymes synthesized by T. trogii was detected as 11100 U/L for Lac, 2.5 U/L for LiP and 4.5 U/L for MnP after 14 days of incubation at 25°C under static conditions, volume ratio of medium/air 1:6, and 3 plugs as inoculum. Among the supplements tested, 5% glycerol increased Lac activity to a significant extent. The addition of 1% veratryl alcohol had a positive effect on MnP.     

The presence of heartwood decay,a precursor to hollow formation,within Eucalyptus camaldulensis in relation to stem size

River Red Gums (Eucalyptus camaldulensis Dehnh.) are large trees that dominated many of continental Australia's riparian areas, providing abundant hollows for nesting and denning fauna. Land clearing and forestry have reduced the availability of large trees, and much of the remaining forest is dominated by small regrowth trees that lack visible hollow entrances. Inspection of recently felled River Red Gums revealed that heartwood decay, a precursor of hollow formation, can be common in relatively small trees. Internal decay and voids remain inaccessible until stochastic damage exposes them, which may not occur until the tree is old, and hence probably large. This discrepancy indicates that there is likely to be a size range of trees into which artificial entrances can be added to quickly increase hollow availability in landscapes undergoing active restoration as fauna habitat.     

Heterothallism revealed in the root rot fungi Berkeleyomyces basicola and B. rouxiae

Berkeleyomyces basicola and Berkeleyomyces rouxiae, two sister species previously treated collectively as Thielaviopsis basicola, reside in the Ceratocystidaceae (Microascales, Ascomycota). Both species are important root pathogens of many important agricultural crops and ornamental plants. Although T. basicola has been known for more than 150y, a sexual state has never been found and it has been assumed to be an asexual pathogen. The aim of this study was to determine the mating strategy of the two Berkeleyomyces species. Investigation of the genome sequences of two B. basicola isolates allowed for the complete characterization of the MATlocus, revealing that it has a typical heterothallic mating system with the MAT1-1andMAT1-2 idiomorphs occurring in different isolates. PCR amplification using mating type primers developed in this study, showed that the MAT1-1-1andMAT1-2-1 genes were also present in different isolates of B. rouxiae. Pairing of isolates representing the two mating types of both species,using a variety of techniques failed to produce sexual structures. Although we have found no direct evidence that they reproduce sexually, these fungi are clearly heterothallic with both mating types occurring in some countries suggesting that a cryptic sexual cycle could exist for them.